Ensure the external drive isn't being indexed by the OS, this might also represent a hook the OS has on the external drive.
You can also check to ensure System Restore isn't active on it, it shouldn't be by default.

DRIVE IMAGINGInvest a little time and energy in a well thought out BACKUP regimen and you will have minimal down time, and headache.

Just guessing here, but I have doubts that logging off would necessarily end the service or process that is locking the drive. When a computer here is logged off, I can still access shared folders on it, automatic backups still run on time, etc. Seems to me that putting it to sleep might have a better chance, although I seem to remember reading once that that may not be enough. Also re hoping for MS to hear your plea to fix it - people have been complaining about this since Win XP and MS can't get it right.

Ensure the external drive isn't being indexed by the OS, this might also represent a hook the OS has on the external drive.
You can also check to ensure System Restore isn't active on it, it shouldn't be by default.

Hi, Clint,

I appreciate the ideas, but I'm not sure how to determine whether the external drive is being indexed by the OS. I don't think System Restore is active on it, but again, I'm not sure how to verify that. If anyone can advise how to do that, I'd be most grateful.

Just guessing here, but I have doubts that logging off would necessarily end the service or process that is locking the drive. When a computer here is logged off, I can still access shared folders on it, automatic backups still run on time, etc. Seems to me that putting it to sleep might have a better chance, although I seem to remember reading once that that may not be enough. Also re hoping for MS to hear your plea to fix it - people have been complaining about this since Win XP and MS can't get it right.

As I indicated in my reply to mrjimphelps, I wasn't sure about the logging off idea as a solution, though I'd be happy if it worked, happier still if MS would actually solve the problem for all of us, instead of making us do endless workarounds. However, I know you're right about this sort of thing being a problem even in XP, as I occasionally had similar problems with certain flash drives even under XP. What's interesting here is that it's now W7 that's hanging on to the drive, while that same drive gets released perfectly in two XP machines. Go figure. You're also right about not holding my breath till MS fixes this problem; I'd be "Little Boy Blue" a long time before that happens!

I once unplugged an external hard drive after running a backup and forgot to click the Safely Remove icon, and I got a message saying that the write cache hadn't finished (or something like that). So I always make it a point to click the icon whenever possible when using the external hard drive. If you get the message "Windows cannot stop the device because a program is using it," try closing the program in the Task Manager. Be sure that all (Windows) Explorer windows are closed. You might have to log off Windows and then log on again, but that is better than losing data. Why take a chance?
I found that a program called Process Explorer from Windows SysInternals can show which program is using a device.

SRH protects against losing cached data not yet written

Hi All: I must agree with GS's assessment. Since before Windows, back in the DOS 4-5-6 days, Microsoft chose to make caching data writes as the default, to fool users into thinking their PC/OS's were faster than they really are by caching disk writes. This continues thru today, which is often why you will see your drive lights flashing when you "think" nothing is running. They are just "catching up" with the data needing to be written out to the device. This is particularly an issue with thumb drives today. I have several different thumb drives I use regularly, a few of which will "never" eject or SRH, and a few which will occasionally fail to SRH. In each of those cases, it was after I had transferred a large amount of data to the thumb drive -- either in lots of files or a few files with big file size. I fully believe this is completely due to cached writes to the thumb drive (which is much slower than SSD or mechanical hard drives). In frustration I have tried to just pull the thumb drive a few times, but after having the entire thumb drive corrupted and needing to be re-formatted to work again, I just pay attention to the non-SRH message, and if I need it sooner, I shutdown the PC (even logging off has proven not 101% safer). My two cents. Rob

Something you can try is to turn off Write Caching for you USB drive. Here's how...

WARNING: This procedure will restart the computer after clicking the final "OK".
You should save and close anything else that you are working on first.

- Plug in your USB drive
- Open the Control Panel (icons view)
- Click on the Device Manager icon
- In Device Manger, double click on "Disk drives" to expand it
- Double click on your USB drive (this will work for any drive)
- Click on the Polices tab
- Select Quick removal
- Click on OK.
- Click on Yes to restart the computer to apply.

I hope this helps.
We all have run into your problem.
Since Windows 3.1, the operating system has been trying to do "everything" for us.
This is fine for newbies, but it drives us power user crazy.
A lot of times, Windows will try to make things easier, but will do the wrong thing.
I miss 3.1... Make it run, and it will stay running...

Greetings from the cold and frosty Cotswolds,
I have a slightly different problem with ejecting flash drives from my Win7 laptop; it doesn't identify anything to eject, even though it knows there's one there and I can access it through explorer and eject it from there. It doesn't show in Device Manager either, nor does my bluetooth mouse or keyboard, as they all did until a couple of weeks ago. (Oddly around the same time that my Office 2010 decided it need registering again but doesn't provide an installation code to quote...)

Al sorry this is so late. I'm sure you've solved this all ready. if not:
Go tot device manager in control panel and click disk drives.
select the usb drive (or drives) and select properties.
under profiles enable write caching for that drive. (just remember you'll always have to use safely remove instead of just turning your drive off)
I had this same issue on dozens of clients systems and the above solved the problem.
Hope it helps.

Many thanks to all of you for the suggestions. I have to confess that I'm a little bemused by advice to turn off write caching and advice to turn on write caching, all within the space of three posts, but what the heck, I'm easy; I'm willing to try both! As to that freeware program Unlocker, I've downloaded it and have given it a try with PDF files that won't delete and so far it works like a charm. I haven't yet had occasion to try it on the 1TB USB HDD which was the subject of my original post, but will report back when I've given that a test. I'm still puzzled as to why W7 won't let go of my HDD while two other XP machines let it go perfectly every time, but perhaps that's just another "Microsoft Mystery" that will never be solved (nor, of course, ever resolved by MS, as it rightly should be).

Well, I've run a test and here's what I found. I plugged in my 1TB USB HDD and backed up my W7 desktop, then clicked on the Safely Remove Hardware icon, but (as usual) that didn't work, as I got the message that said, "Windows can't stop your 'Imation M100 USB 3 USB Device' device because a program is still using it. Close any programs that might be using the device, and then try again later." I had always previously backed up this computer through a USB3 port, as both the computer and external HDD are USB3, so this time I ran the backup through a USB2 port, just to see if that might make any difference, but the result was the same. I checked, as per your suggestion, Clint, and both System Restore and Indexing were NOT active on this drive. As to Write Caching, it is currently set on Quick Removal, with Write Caching disabled.

While Unlocker has worked beautifully for me on files, it obviously isn't able to help me with this HDD.

Well, there you have it, folks, the latest from the Micro$oft frustration front. Many thanks to all of you for your various ideas and suggestions; if I'm still missing something obvious, please let me know.

I just scanned back through the thread and may have missed it, but what software are you using for your backups?

Create a new drive image before making system changes, in case you need to start over!

"Let them that don't want it have memories of not gettin' any." "Gratitude is riches and complaint is poverty and the worst I ever had was wonderful." Brother Dave Gardner "Experience is what you get when you're looking for something else." Sir Thomas Robert Deware. "The problem is not the problem. The problem is your attitude about the problem. Savvy?" Captain Jack Sparrow. Unleash Windows